LOURDES, France (AP) _ A Sicilian woman's malignant tumor has been cured following her pilgrimage to Lourdes, religious authorities said Thursday, declaring it the 65th miracle at the Roman Catholic shrine.

Dr. Theodore Mangiapan, head of the Medical Bureau of Lourdes, said his panel and two other church medical commissions had determined that Delizia Cirolli's cure could not be explained medically.

In Catania, Sicily, Archbishop Luigi Bommarito said investigators had ''acknowledged the 'miraculous' character'' of her case.

Miss Cirolli, 24, visited Lourdes in August 1976, suffering from a malignant tumor in her right leg. Doctors had said they should amputate the leg, but soon after her pilgrimage, the tumor began to heal, Mangiapan said.

''Delizia never received any specific treatment, neither surgery, nor physiotherapy nor chemotherapy and she had only one thing to do and that was to die,'' he said.

Her health was monitored closely, allowing medical authorities to note that her cure was ''perfect and definitive,'' a requirement for a cure to be recognized as a miracle.

The grotto at Lourdes became a shrine after a girl named Bernadette Soubirous had 18 visions of the Virgin Mary recognized by the church starting in 1858.

More than 4 million people from as many as 150 countries travel to Lourdes annually seeking the water from the grotto.

Miss Cirolli's healing was the 65th miracle recognized at Lourdes since 1862, although there have been more than 6,000 claimed recoveries. There are about 2,500 cases waiting to be declared miracles.